Need help diagnosing trans problem 200-4r

[TurboBuickSix]

I had my trans rebuilt a few years ago and it has worked great since then. But all of a sudden it shifts early and soft compared to before. I checked the fluid and TV cable and they both are ok. The trans seems to be fine otherwise,no noise,goes through all the gears(but earlier than b4),no flaring etc. It just won't shift hard like it was,before it chirped the tires very hard now it will not. It is going through the gears really quick compared to before when it would build some rpm before the shift. Now it feels like a stock trans. I'm hoping it's a stuck valve inside or the servo is stuck but not sure where to start.Please give me your experienced expert suggestions on what to do,I'm not driving anymore until I get this sorted out.TIA

[TurboBuickSix]

Another thing I should mention. Before this problem started when in WOT in either 2nd or 3rd gear (not near shift points but in the middle of the gear) it seemed to disengage or slip for just a split second as if it was going into nuetral for a half second. It would quickly re-engage and break the tires loose and continue accelerating.

[turbo nasty]

Time to drop the pan and take a look at whats in it and how the fluid looks

[TurboBuickSix]

Originally Posted by turbo nasty

Time to drop the pan and take a look at whats in it and how the fluid looks

Dropped the pan last night,fluid looks ok but not optimal as it needed a change anyhow. There was a little black gunk on the magnet but otherwise the pan was very clean. Drove it again before this and it is definitly shifting earlier and softer than it always has. I'm trying to find a transmission gauge to find out what the pressures are,I will post the results when I get them. I am also considering just bringing the car to the shop that did the tranny in the first place. I'm not mad it lasted longer than I had expected anyways if it turns out to need a rebuild. This was a modified 4BQ trans with 2800 restalled D5 from my old 84 T. I have no idea what they did inside but it has held up to some abuse.My car seemed to hit a limit of around 112-115 in the quarter,maybe this tranny and convertor was holding me back some?

[turbo nasty]

Sounds like it took a beating.
How many miles?

[TurboBuickSix]

Originally Posted by turbo nasty

Sounds like it took a beating.
How many miles?

Only about 16k.any suggestions on what to check while the pan is off?

[turbo nasty]

Originally Posted by TurboBuickSix

. I'm not mad it lasted longer than I had expected anyways if it turns out to need a rebuild.

A stock trans with a shift kit running in the low 12's high 11's should last longer than 16 k miles. That pretty good MPH what is your build/bolt ons?

What level did you have the fluid in the pan when driving it?
Middle part of the back and forth bends on the dipstick?


Cavatation can cause flare or bad slide shift on the 2-3 from low fluid level

[TurboBuickSix]

Originally Posted by turbo nasty

A stock trans with a shift kit running in the low 12's high 11's should last longer than 16 k miles. That pretty good MPH what is your build/bolt ons?

What level did you have the fluid in the pan when driving it?
Middle part of the back and forth bends on the dipstick?


Cavatation can cause flare or bad slide shift on the 2-3 from low fluid level

Yes the level was approx middle of the bends. Never did it before,not even with the BFG DR's or 10" wide street tires I had before. I have skinny regular tires on there for the time being that spin like they are coated with butter so I don't think I'm accelerating too hard right now at all. Bolt on's are home ported heads,home built shortblock with hyper pistons and 204/214 cam,TE-60 with bleeder valve type boost control,65lb inj,Mease(TH style) 3" downpipe and cutout,stock 2 1/4" exhaust with dual mufflers(monte ss style),powerstoke intercooler,ported intake,walbro fuel pump and adj reg,older TT chip,air bags,stock ignition,f-body radiator and separate external oil and trans colers in front of IC,water/oil separator inline with pcv valve,egt,boost,oil,temp,and knock gauges,big mouth cold air kit with 9"k&n,stock headers no leaks,power plate,drive shaft loop,lock up switch,fan control switch. I know alot of this stuff has nothing to do with the trans but I thought I would list everything I could think of then put it in my sig later.

[turbo nasty]

If they go back through it make sure at the minimum you have a bigger boost valve in the psi reg set up no smaller than .500.

Get the psi's and post em up first

Then id take it back to em and see what they say, that mileage is to low IMO.

[chris718]

Based on the description you are giving it sounfds like the inner tv valve is sticking.Give me a ring and Iwill tell you how to try to free it up if that is the issue.631 218 1989